condition mean min max ZT0-3 3.091743333333333 2.08742 4.220599999999999 ZT4-7 4.645099999999999 4.645099999999999 4.645099999999999 ZT8-11 4.42198 4.42198 4.42198 ZT12-15 3.9086499999999997 3.46198 4.35532 ZT16-19 3.3217350000000003 3.3217350000000003 3.3217350000000003 ZT20-23 2.178225 2.178225 2.178225